Throttle control mechanism



March 24, 1936. 3 CUMMINS 2,034,745

THROTTLE CONTROL MECHANISM Original Filed Oct. 26, 1954 Patented Mar.24, 1936 UNHTED STATES 2,034,745 THROTTLE CONTROL MECHANISM Clessie L.Cummins, Columbus, Ind., assignor to Oil Engine Development Company,Columbus,

Ind., a, corporation of Indiana Original application October 26, 1934,Serial No.

750,127. Divided and 1935, Serial No. 28,908

this application June 28,

2 Claims. (01. 105-48) My invention relates to a throttle controlmechanism for internal combustion engines, particularly oil engines, andis concerned primarily with a mechanism for preventing the movement ofthe throttle to full open position until the vehicle propelled, orgenerally the load moved, thereby has attained a. predetermined speed.

This application is a division of my copending application for athrottle control mechanism, Serial No. 750,127, filed October 26, 1934.

It is characteristic of oil engines that practically their full power isavailable when starting under load. This condition is advantageous wherethe principal operative requirement is rapid acceleration, but is apositive detriment unless properly controlled where, for example, theengine furnishes the motive power for a shifting locomotive in arailroad yard. Because of the high starting torque of the engine, thetendency of the shifting crew is to couple as many cars as thelocomotive is capable of moving from a standing start, with the resultthat the train cannot be accelerated and therefore is moved at a slowerrate of speed than is demanded by efficient shifting service.

It is therefore desirable to provide a mechanism which prevents theutilization of the full power of the engine when starting under load byinterposing a stop in the path of movement of the throttle lever shortof the latters full load position, and which is automatically shifted toa clear position when the locomotive, for example, attains apredetermined speed, and further, in which the relation between the stopand throttle lever is such that the latter may be moved from full-loadto no-load position, notwithstanding that the stop may then be occupyingan interrupting position due to a decrease in the train speed.

The principal object of the present invention is to devise a mechanismhaving the above characteristic which is adapted for operation by one ofthe power sources that are customarily available on track vehicles, forexample, namely, electricity that is ordinarily employed for lighting,or

other auxiliary functions.

These and further objects of my invention will be set forth in thefollowing specification, reference being had to the accompanyingdrawing, and the novel means by which said objects are eifectuated willbe definitely pointed out in the claims.

In the drawing, the figure is a diagrammatic view, partly in section,showing a mechanically controlled, electric circuit for limiting themovement of the throttle lever towards full-load position, the leverbeing shown in the maximum position which it may assume until thelocomitive attains a predetermined speed.

Referring to the drawing, the numeral l designates the wheel of alocomotive, for example, which is mounted on the usual axle ll that mayhave affixed thereto a pulley l2. A belt l3 operates over the pulley I 2and also over a second pulley I l secured to a shaft l5 which isjournaled in a suitable bearing I 6. The shaft l5 extends to the left ofthe bearing and has afiixed thereto a pair of arms I! upon which arepivotally mounted a pair of fly-ball levers I8, the inner arms IQ ofwhich are in constant bearing engagement with one end of a sleeve 2!]that is journaled upon an extension 2! of the shaft l5. The left end ofthe sleeve is formed with an annular channel 22 and a coil spring 23,which encircles the left extremity of the extension 2|, bears againstthe left end of the sleeve and also against the head 24 provided on theextension 2!. The tendency of the spring 23 to extend in length causesthe sleeve 20 to bear constantly against the lever arms l9. a

A rock lever 25 is pivoted at 26 upon a convenient supporting structureand the upper end of the lever is formed as a nose for constantretention in the annular channel 22. The lever may also carry anelectrical contact 21 which is adapted. to bear against a second contact28 that is connected by a lead 29 to one end of a solenoid coil 30. Thecontact 2'! is connected to the opposite' end of this coil by a lead 3!,a source of electrical energy 32, and a second lead 33.

A magnetic core 34 is slidably mounted within the solenoid and isprovided with a stop 35 which is normally actuated outwardly by a coilspring 36 to an interrupting position with the lower end of a throttlelever 31 that is pivoted as at 38. The no-load position of the throttlelever is indicated by the dotted line 39 and the full-load positionthereof by the dotted line 40, the lever being shown in the maximumposition to which it can be moved owing to its engagement with the stop35. Preferably, the lower end of the lever 31 and the upper end of thestop 35 are provided with inclined cam surfaces M and 42, respectively,so that the throttle lever can be returned to the no-load position fromany position between the intermediate position, as shown, and thefull-load position, notwithstanding that the stop 28 may be occupyingthe position shown in the figure. A situation of this kind might occur,for example, when the locomotive 2 is ascending a grade with thethrottle lever in full-load position and it is desired to bring thetrain to a stop. During this return movement, it will be obvious thatthe cam surfaces will cause the stop to be moved downwardly in the coiluntil the lever 31 has clearedthe upper end of the stop.

In the relation of the parts as shown, the interrupting position of thestop 35 is indicated as permitting a movement of the throttle leverthrough approximately twothirds of its range from the no-load position,although this relation may be varied as desired. In the operation ofthis mechanism, the fly-balls ill will be adjusted so that, at somepredetermined speed of the locomotive, they will move outwardlysufficiently to cause the sliding of the sleeve 23 toward the left andconsequently a closing of the contacts 21 and 28 to thereby complete theelectrical circuit which includes the solenoid coil 30. The magneticcondition thereby established around the core 34 draws the latterdownwardly against the spring 36 until the stop 35 has reached aposition clear of the lower end of the throttle lever. This releasingmovement of the fly-balls may be set for as low as a speed of five milesper hour, or at any speed at which the operating requirementsdemand.When the speed of the locomotive falls below the indicated criticalspeed, the stop will be returned to interrupting position by the spring36, since the electric circuit is then broken. 7

It will be obvious that the rock arm 25 may possess other mechanicalconformations than that shown, since the generic construction involvedis the closing of an electric circuit by a mechanical governor devicethat is responsive to the speed of the vehicle.

It is apparent that the shifting crew is positively prevented fromcoupling more cars to the locomotive than the latter can initially movefor the throttle opening indicated. Therefore, there is always provideda sufficient reserve of power to insure a desirable acceleration of thecoupled train and it is contemplated that, after the mechanism is onceadjusted, it will be incapable of unauthorized change by the train crew.Moreover, the mechanism is designed to make use of a source of powerthat is customarily available in railway service, so that no additionalauxiliaries are required.

It is to be understood, however, that no restrictive interpretation isto be placed on the application of my mechanism to the field of railwayservice, in view of the above disclosure, since the essential conceptioninvolved is capable of other and broader uses in the art of enginecontrols. For example, in hoisting apparatus, crane or steam shovelinstallations and similar appliances, it may be desirable to arrange fora power reserve, such that the load which the engine could initiallymove would be restricted to a degree permitting. subsequentacceleration. The term vehicle, therefore, is employed in its broaderaspect as being an instrument of conveyance.

I claim:

1. A throttle control mechanism for an engine driven vehicle comprisingin combination, a throttle lever operable between no-load and fullloadpositions, a solenoid, a magnetic core operable in the solenoid andhaving a stop projecting externally thereof, means tending to hold thestop in a position to limit the movement of the lever to a predeterminedintermediate position when moved towards full-load position, amechanical governor device controlled by the speed of the vehicle, andan electrical circuit including the solenoid, a source of electricalenergy, and means actuated by the governor device to close the circuitand cause a retraction of the magnetic core sufficient to free thethrottle lever for continued movement toward full-load position when thevehicle attains a predetermined speed.

2. A throttle control mechanism for an engine driven vehicle comprisingin combination, a

throttle lever operable between no-load and fullload positions, asolenoid, a magnetic core operable in the solenoid and having a stopprojecting externally thereof, a spring tending to hold the stop in aposition to limit the movement of the lever to a predeterminedintermediate position when moved toward full-load position, a mechanicalgovernor device controlled by the speed of the vehicle, a normally openelectrical circuit including the solenoid and the source of electricalenergy, and a switch arm moved by the governor device to close thecircuit and cause a retraction of the magnetic core sufiicient to freethe throttle lever for continued movement toward fullload position whenthe vehicle attains a predetermined speed.

CLESSIE L. CUMMINS.

